Apparatus for timing watches



Dec. 15, 1936. E. NORRMAN 2,064,559v

APPARATUS FOR TIMING WATCHES FiledvFeb. 14, 1936 2 Sheets-Sheet 1 @'vjl O AMPLIFIER ATTORNEYS Dec. l5, 1936. E, NORRMAN 4 2,064,559

APPARATUS FOR TIMING WATCHES Filed Feb. 14, 1936 2 Sheets-Sheet 2 18 @ai-3 so 5 7 lNvEN-roR .6R/vs? Nom-WAN ATTORNEYS Patented Dec. ll5, 19356- PATENT ori-ICE UNITED STATES Claims.

watches which, if the maximum accuracy is to be maintained must be adjusted for changes in temperature and for the changes in the position in which they may be carried. For example, a watch can be so adjusted that it will vary less 'than five seconds per day when held in any one of fivejpositions. When it is noted that the adjustment to such accuracy requires repeated testing of the running and repeated stoni'ng of the bearings until by the cut and try method the required accuracy is obtained, it is obvious that without precision instrumentalities a long time `may elapse after a watch is assembled before it is ready for delivery. In -a watch repair shop such time requirement delays return of the watch .to theV customer. In a factory such a time interval means a tie up of capital and unavoidable delay in lling orders, particularly special orders.

If, for example, it is possible to read the time of the watch to an accuracy of only one second then a considerable period is necessary to detect is suiiicient to determine a similar variation. 35 rI lhe present invention in its preferred embodif ment provides an apparatus for timing watches as compared with a rotating dial, one graduation of which 'represents a variation o! 1/100 of a second, and inasmuch as it is possible ox'-, 40 dinarily to read to a fraction ,ofi the graduation it is possible to detect even smaller variations.

The invention provides furthermore an improved arrangement for timing watches whereby a master watch may be used as the source for the correct standard rate and the rotating dial or its equivalent may be driven at a rate which only approximates the lcorrect rate such, for example, as may be obtained from a motor operated by the usually available alternating current or even by direct current using a suitable motor with an adjustable speeld control.

The present invention has' been developed more particularly in producing an apparatus for testing watches for adjustment or regulation and for the purposes of disclosure of the principles a variation which should be corrected. but if the watch can be read to an accuracy of -1/ 100 of asecond a correspondingly shorter period of time Russa-1D VEB it 1ere oi the invention such an apparatus will be de-- scribed, reference being had to the accompanying drawings` forming a 'part hereof and in which:

Figure 1 is a diagrammatic' view of an illustra- 5 tive arrangement showing the face of the instrument and showing diagrammatically the microphone and amplifier arrangement,

Fig. 2 is-a view in elevation of the same, Fig. 3 is a circuit diagram indicating'connecd 10 tions whereby an alternating current source may be utilized and showing one of the amplifier circuits in detail.

Fig. 4 is a sectional view of one of the switches. The apparatus to be described for the purposes 15 of' illustration comprises an instrument 6 having a rotatable graduated dial 6 which may be `mounted on the shaft of a motor l within the instrument casing. The motor is preferably a synchronous motor driven at a constant speed from a suitable alternating current source. The top of the casing is formed to provide an adjustable disk 8- formed with a window 9 and at the center thereoi.I an index III for framing the reference dial with respect to the ticks of the master watch. A somewhat similar window I i is provided having, if (desired,v a central index I2 for studying the action of the watch to be tested. d

Two tick-responsive devices such as microphones I5, I6 are provided having suitable supports to receive the master watch I1 and the watch to be tested I8.

The rotable dial 6 may be made of translucent material with black graduation marks and numerals whereby it can be illuminated from beneath for the purposes of reading. This arrangement is in some'respectsmre practical than an arrangement in winch 'the disk is opaque and illuminated on its face. The dial as shown 40 has one hundred graduations divided'into five groups with similar markings to correspond to the ve ticks of a watch. For watches with a diilerent number of ticks a correspondingly different dial may be substituted.

As the microphone I5 responds to the ticks of the master watch I1, the impulse is amplified and shortened to provide a momentary current for illuminating the neon ash lamp I9 beneath the transparent dial 6 at the window 9. 50

yProvision is made for relative adjustment between the`rotating dial 'and the index I0 whereby the zero ot the dial may be brought into regisltration with the index III. As shown, the ad- Justable disk 8 in which the windows are formed 55 is rotatably adjustable in the casing, a handle 20 being provided to facilitate adjustment. If only a minor adjustment of the disk is necessary to correctly frame the dial this is more conveniently done by a slight movement ofthe disk 8.l If a greater adjustment is necessary, or in any event if desired, the adjustment for framing may be made by rotating the motor engaged by a pinion 22/ on a vertical shaft 23 to the top of which is secured a suitable thumb Wheel 24.

As the microphone I6 responds to the ticks of the watch to be tested, I8, the impulse is amplified and shortened to provide a momentary current for illuminating the neon lamp or lamps 25 beneath the dial 6 at the window il. Three lamps are shown as giving a wider` field of. illumination than one lamp. Otherwise the operation is the same. An adjustable hand 26 which may be operated by a thumb nut 21 is provided at the window and can be adjusted to show the position of a zero of the dial when the dial is suitably framed to bring a position of the dial opposite the index during flashes from the watch ticks of the master watch.

It will be seen that the arrangement described makes provision for framing the dial relative to the index I0 and then adjusting the hand 26 to the zero as illuminated from the watch to be tested. `Furthermore, re-framing is possible in the event of a shift of the dial relative to the index of the master watch during which re-framing the relation between the index l0 and the hand 26 is maintained. In other words, the hand 26, which also is anindex, in its adjusted position moves with t e index ill.

In order to ascertain theg in, or loss of the watch being tested the dial framed with ref-v reasons which will be seen upon analysis ofthe operation of the device.

For the 'purposes of illustration the watch supports may be carried by ball and socket. joints on fixed bases, the ball and socket connection permitting movement of the support to any of the desired positions in which thel running of the watch is to be tested. Ordinarily the master chronometer or watch support need not be adjustable for obvious reasons.

The watch holder is preferably carried by a sponge rubber or other suitable packing or damping element in yorder to avoid the effect of extraneous noises and jars which might otherwise excite the microphone button. This microphone is sensitive to the ticks of the watch but insensitive to room noises or jars. Across each microphone circuit a rheostat for adjusting its sensitivity may be connected.

The electrical circuit of each of the amplifiers indicated at 30 and 3| in Fig. l and shown in detail in the electrical diagram, Fig. 3, is substantially the same as the circuit shown in my co-pending application, Ser. No. 670,267, filed May 10th, 1933 and includes both amplifying and impulse shortening circuits. In each amplifier circuit a condenser 33 (33') is charged slowly through a resistance from a battery 34 (34') between ticks of the Watch so that upon the occurrence of a tick a relatively strong electrical impulse is supplied by the condenser which-serves as a principal source of voltage at the instant of the impulse.

The first two stages of amplification including the input transformer 35 and amplifier tubes 36 and 31 may be arranged in accordance with standard practice for a resistance coupledamplifier. The third vacuum tube 38 employs a special circuit which may be called thetime limiting circuit. The control grid of this tube preferably is biased to such a high negative potential that no plate current or at least a very Weak one, is flowing through the tube as long as the grid is not disturbed by impulses from the previous stage. A small condenser 4U, which serves a's a source of voltage is slowly charged through a very high value resistor 4I. A glow discharge tube 38a or a spark gap may be included in the plate circuit as shown. This tube is usually not necessary but is of value if it is desirable to first amplifier tubemay also be biased approximately to cut off if desired.

The operation of the time limiting circuit is as follows. When the condenser 40 has been charged the circuit is Iat equilibrium, no current flowing in any part. When an impulse in a positive direction is impressed on the control grid of the tube 38, thisl tube will pass current and the condenser 40 discharges through the primary of the transformer 39. The time it takes for the condenser to discharge depends on its capacity and on the impedance of the primary winding of the transformer 39 and also on the plate impedance of the tube. By choosing the proper constants, impulses of very short dura-I tion may be obtained. After the 'condenser 40 is discharged practically no current will flow through the tube on account of the high value of the resistor 4|, through which the condenser 40 is charged relatively slowly.'

By this circuit arrangement impulses (A. C. or D. C.) of a relatively long duration Will give output impulses of very short duration of the order of 1/l,000 or 1/10,000 of a second. The condenser is slowly charged through the resistor 4|, during the silent interval between the impulses an. so the cycle repeats itself. The auxiliary grid of the vacuum tube 38 is connected to the plate side of the resistor 4|. Thus this member has no voltage applied to it unless the condenser 40 is charged. This improves the time limiting action of the circuit.

The control grid of the output tube 42 is biased to or near cut off in order that it should not pass any current except when the grid is ex cited from the previous amplifier stage. A blocking resistor 44 and a storage condenser 43 are connected as shown to supply operating voltage to the lamps 25 in this circuit. The lamps 25 herein shown are neon lamps suitably designed to provide the desired instantaneous flash to illuminate the dial.

If desired earphones 45 may be added to the circuit for the watch to be tested to make audible the tick induced impulse.

-the escapement is It is seldom that the time interval between two successive ticks is exactly the same, perhaps because the escapement is not perfectly centred. For this reason if the flash lamps 25 are .lighted in response to each tick ofthe watch the device will show an apparent hunting of the range of which will indicate the extent to which inaccurately centred and whether correction is neccessary. For timing purposes it is preferable to avoid this hunting and this may be accomplished by a provision whereby the lamps 25 are energized by alternate ticks only. 'I'his can b accomplished .by varying the time of recharging of one of the condensers, for example, condenser l0. For this purpose, the several constants of the circuit are suitably chosen and the resistor 4i is made sufcient to prevent charging of condenser 40 be tween two successive grid impulses caused by the watch ticks while permitting an adequate chargel during two intervals. Furthermore, this resistor is made adjustable in order that operation in either way mayV possible, that is to say, operation to determine the difference between the two tick intervals and operation for timing the running of the watch. By further adjustment the time of charge may be even further lextended to provide longer intervals between responses if desired. The bias resistance of the first ampliler tube 38 should be high to cause the tube to act as a rectifier. The vneon lamp or spark gap` serves to prevent a discharge of the condenser 46 before it reaches the break-down voltage of this tube or gap.

The power for the amplifying circuit may conveniently be supplied from an A. C. current which also'operaltes the motor of the reference dial. In the arrangement illustrated the A. C. line current passes through the-primary 46a 0f a transformer 46 which transformer through a secondary winding supplies current tothe fila.-l

ments of the tubes. A rectifier tube 48 provides direct current to the +B circuit. The arrangements giving the +B, B and -C voltages are conventional and are sufficiently illustrated in the drawings.

A more positive method of insuring response to only alternate ticks of the watch thereby to prevent the appearance of hunting may be provided in accordance with the arrangement shown in Figs. 2 and 4. rAs there shown a commutator 56 which is connected t0 the motor shaft.

by' gearing I5| and 52 to rotate once during aneven number of ticks of the watch. In the arrangement indicated, assuming a dial 6 divided into lfive similar sections for a ve tick watch the gearingratio may be 4 to 5. This commutator is provided with an annular conducting section 53 and another section 54 which is divided into an even number of conducting and nonconducting sections to correspond to the numobserving the operation and relation of the ticks at both ends of the swing of the balance wheel. When the watch isA examined for timing and response from 4alternate ticks is desired, the brushes are moved laterally so that at least one brush bears on the segmented portion of the armature. Ordinarily a device for eliminating response to alternate ticks of the master watch is less important but such is indicated at 50', 5I' in Fig. 1.

Operation In operation the watch or watches to be tested are placed against the microphone or microphones I6 and compared with the master chronometer. After a denite interval, as for example, two minutes, each watch is again compared to determine whether it is gaining or 1os. ing and how much. This procedure is repeated with the watches held in each position for which tests are desired. The method /of`comparison involves first framing the dial with respect to the master watch a-nd if -a number of watches are being tested reading the dial at the index I2 and making a record, which after the selected interval is compared with another record similarly made. If only one watch is being tested, then the dial is framed with respect to the master watch by the index I 0 and the index hand 26 is adjusted to the zero position in `the window -its proper positionis not disturbed by the reframing of the dial. -The expression framing the dial" is. used to indicate the operation of bringing together the zero reading and the index I0. The dial should be shaded from any bright light for easy readings. For accuracy the dial should be again framed when taking the second set of readings after a time interval. Furthermore if the impulses from alternate ticks Vare eliminated in effect, accuracy will be better insured if repeated readings are taken to be sure to use either the responses from what may be termed the fast ticks or those from the slow ticks in each case. It will be remembered that the time intervals between ticks is not uniform and if the dialis first framed for the fast tick and for second reading is'framed for the slow tick or if a tested watch is similarly timed an error amounting tothe different of the tick intervals will be introduced. For obvious reasons it is usually more certain and simpler to frame the dial with reference to the master watch, while the circuit is responsive to both the fast and slow ticks of the master watch, using, for example, the fast tick which can be distinguished. Obviously this is of minor importance until close adjustment of the watch is approached.

The electrical responses may be explained as follows: When the voltage of the controligr-id of the tube 38 swings in a positive direction the plate impedance of the tube decreases and' the neon tube, 38a, breaks down and passes current. The condenser 40 discharges through the primary of the transformer 39. The impulse is passed by the secondary winding of the transformer 39 to the control grid of the output tube 42. This tube will pass plate current and so flash the neon lamps 25. 0n account of the high resistance of resistor li the condenser 46 will not be charged sufilciently to break through the neon lamp' 36a or spark gap the first time thereafter that the grid of the tube 38 swings positive and no-output impulse will be obtained. This'cycle will repeat itself.

The foregoing particular description is illustrative merely'and is not intended as defining the limits of the invention. Numerous variations may be made, for example if the reference member is driven With suilicient accuracy the master watch becomes unnecessary.

1. An apparatus for timing watches comprising, in combination, a motor and a reference dial constantly driven thereby, an index member adjacent said dial, a second index member adjacent said dial'spaced from the first mentioned index member, means for mounting the motor and index members for relative adjustment to frame the dial, a flash lamp for illuminating the reference dial adjacent the first mentioned index member, a second flash lamp `f`or illuminating the reference dial adjacent the the ticks of'a master Watch and the watch to i be tested respectively.

2. Apparatus for timing watches, as defined in claim 1, wherein the motor and the dial are rotatably mounted for movement relative to the index members to frame the dial with respect to one index member.

3. Apparatus for timing watches, as defined in claim 1, wherein the second index member is adjustable relative .to the first index member and wherein the framing means adjusts the relation between the dial and both index members equally.

4. Apparatus for timing watches, as defined in claim 1, wherein the index members are movable together circumferentially o f the dial to frame the dial with respect to the first mentioned index member and one index member is independently movable circumferentially of the dial relative -to the other index member.

5. An apparatus for timing watches comprisiing a constantly driven graduated dial, two index members adjacent said dial and spaced from each other, flash lamps positioned to illuminate said graduated dial adjacent the index members respectively, 'means for energizing said flash lamps respectively from a master watch and from a watch to be tested comprising tick responsive devices, an amplifier connected to energizing circuit connected to each amplifier to be energized by a tick impulse to trigger the current through the flash lamp.

6. An apparatus for timing Watches comprising a. constantly driven graduated dial, two index members adjacent said dial and spaced from each other, flash lamps positioned to illuminate said graduated dial adjacent the index members respectively, lamps respectively from a master watch and from a watch to be tested comprising tick responsive devices, an amplifier connected to each tick responsive device and, connected to each amplifier, a flash lamp energizing circuit comprising a condenser, a resistance through which the condenser is slowly vcharged and a tube the grid of which is connected to the amplifier to be energized by the tick impulse to trigger th discharge through the flash lamp.

'7. An apparatus for timing watches comprising a constantly driven graduated dial having repeating sections similarly graduated and of alength to be similarly illuminated at the time of successive ticks of a watch, two index members adjacent said dial, two flash lamps positioned to illuminate said graduated dial adjacent said index members, means for energizing said flash lamps respectively from a master watch and from a Watch to be tested comprising tick responsive devices to receive respectively the master watch and the watch to be tested, two amplifiers connected respectively to said tick responsive devices, and flash lamp energizing circuits each comprising a condenser, a resistance through which the condenser is slowly charged and a tube the grid of which is connected to' the respective amplifier to be energized by the tick impulses to trigger the discharge through the flash lamp. Y

8. An apparatus for timing watches as defined in claim 1, characterized in that the circuit for energizing one flash lamp includes means for eliminating the effect of alternate ticks of the watch.

9. An apparatus for timing Watches as defined in claim 5, characterized in that the circuit for energizing one flash lamp includes means for eliminating the effect of alternate ticks of the watch.

10. An apparatus for timing watches as defined in claim '7, characterized in that the circuit for energizing one flash` lamp includes means for eliminating the effect of alternate ticks of the watch.

ERNST NORRMAN.

means for energizing said flashA 

